The Clinical Immunology Society is proposing to develop an intensive 3-4 day course on primary immunodeficiency, geared toward fellows in training, with a primary goal of education on the diagnosis, pathogenesis and treatment of primary immunodeficiency diseases. The secondary goals of the course are to attract and develop future scientists in academic medicine; and to enhance the awareness of clinical immunology and its importance in scientific discoveries and clinical application while effectively "mixing" faculty and students in order to break down the "professor/student" roles. This course will include seven faculty members and will be presented to 25 fellows. The number of participants is intentionally being planned at a lower level, since this will be an "interactive course." The fellows who participate in this course are to be individuals with responsibility for the evaluation and care of patients with primary immunodeficiency. The candidates will be drawn from training programs, hospitals and institutions that are in North, Central or South America. The program will be advertised on the websites of the Clinical Immunology Society and the Pan American Group for Primary Immunodeficiency. In addition, bulletins will be sent to training directors of Allergy/Immunology programs and Infectious Disease Programs. This course will be held in an informal setting. Day one of the course will have intense lectures and discussion. Day two will again involve intense lectures and discussions. Following the discussion, there will be a testing of the application of knowledge previously presented. Day three will again be comprised of lectures and discussions and will end in the early afternoon. Fellows participating in the program will be expected to present a case to the group for discussion. Faculty members will be paid an honorarium of $1,000 and have their travel expenses reimbursed for their participation. Fellows participating in the course will be reimbursed for their travel expenses. No registration fee will be charged for the fellows participating in the program.